Synergistic cellulose hydrolysis can be described in terms of fractal‐like kinetics

Abstract

A fractal-like kinetics model was used to describe the synergistic hydrolysis of bacterial cellulose by Trichoderma reesei cellulases. The synergistic action of intact cellobiohydrolase Cel7A and endoglucanase Cel5A at low enzyme-to-substrate ratios showed an apparent substrate inhibition consistent with a case where two-dimensional (2-D) surface diffusion of the cellobiohydrolase is rate-limiting. The action of Cel7A core and Cel5A was instead consistent with a three-dimensional (3-D) diffusion-based mode of action. The synergistic action of intact Cel7A was far superior to that of the core at a high enzyme-to-substrate ratio, but this effect was gradually reduced at lower enzyme-to-substrate ratios. The apparent fractal kinetics exponent h obtained by nonlinear fit of hydrolysis data to the fractal-like kinetics analogue of a first-order reaction was a useful empirical parameter for assessing the rate retardation and its dependence on the reaction conditions.

The Predominant Molecular State of Bound Enzyme Determines the Strength and Type of Product Inhibition in the Hydrolysis of Recalcitrant Polysaccharides by Processive Enzymes

“…2) ruling out product inhibition as a contributor to rate retardation under our study conditions. Studies of cellulose hydrolysis have shown that decreases in hydrolysis rates seem to correlate with hydrolysis time, and hence, the progress curves have been described using the equations of fractal-like kinetics (60,61). Short hydrolysis times and very low ChiA concentrations (1.0 nM) revealed linear progress curves, with a short lag phase observed at higher 14 C-CNW concentrations (Fig.…”

Biomass processing into ethanol: pretreatment, enzymatic hydrolysis, fermentation, rheology, and mixing

“…Enzymes act in synergy to hydrolyze biomass into sugars [79]. Zhang et al [80] found that without β-glucosidase, the yield of glucose was 57.1%, which increased to 80% after addition of 2.9 mg protein/g glucan of β-glucosidase.…”

Characterization of commercial cellulases and their use in the saccharification of a sugarcane bagasse sample pretreated with dilute sulfuric acid

“…These three enzymes act synergistically to hydrolyze cellulose, creating accessible sites to each other and relieving problems of inhibition by products [12,43].…”